Palladium nanoshell catalysts synthesis on highly ordered pyrolytic graphite for oxygen reduction reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient electrocatalysts is crucial for energy conversion technologies.
• Palladium-based materials are explored as alternatives to platinum for fuel cells.
• Controlled synthesis of nanostructures is key to optimizing catalytic performance.

Purpose of the Study:

• To develop a novel method for synthesizing palladium (Pd) nanoshells on highly ordered pyrolytic graphite (HOPG).
• To evaluate the electrocatalytic activity of Pd nanoshells for the oxygen reduction reaction (ORR).
• To assess the methanol tolerance of Pd nanoshells for potential use in direct methanol fuel cells (DMFC).

Main Methods:

• Palladium thin films and nanoshells were synthesized on HOPG using magnetron sputtering deposition.
• Electrospun poly(ethylene) oxide (PEO) polymer fibers were employed as templates for nanoshell formation.
• Morphology and composition were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray fluorescence spectroscopy (EDX).

Main Results:

• Palladium nanoshells with thicknesses ranging from 25 to 95 nm were successfully synthesized.
• Pd nanoshells exhibited superior electrocatalytic activity towards the ORR compared to Pd thin films of similar dimensions.
• The synthesized Pd nanoshells demonstrated high methanol tolerance, a key advantage over platinum catalysts.

Conclusions:

• The magnetron sputtering technique, utilizing PEO templates, provides an effective route for Pd nanoshell synthesis on HOPG.
• Pd nanoshells represent a promising electrocatalyst for the oxygen reduction reaction.
• The enhanced performance and methanol tolerance position Pd nanoshells as viable electrode materials for direct methanol fuel cells.